Robin Thicke and his girlfriend April Love Geary took a night off from diaper duty to ring in his 41st birthday!

The duo, who just welcomed daughter Mia Love on February 22, celebrated Robin's birthday with a bash at 1 OAK LA on Saturday, and were surrounded by their celeb pals. Lana Del Rey, Lukas Haas, Chanel West Coast and the entire St. Louis Blues team were all on the guest list for the party!

A source revealed to Access that his guests all sang a rousing rendition of "Happy Birthday" before Robin himself hopped on the mic to thanks his friends for feting him.

The West Hollywood hotspot also presented Robin with a 3-tier birthday cake, complete with sparklers! In one snap, Robin seems to be happily blowing out his sparkler candles while his ladylove looks on.